/***********************************************************************
 * BinTrotter : BitTorrent library/client for the Android operating system.
 *  
 * Copyright (C) 2009, Christopher David Stones (chris.stones@gmail.com)
 * 
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 3 of the License, or
 * (at your option) any later version.
 * 
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 * 
 * You should have received a copy of the GNU General Public License
 * along with this program. If not, see <http://www.gnu.org/licenses/>.
 ***********************************************************************/

package org.bintrotter.apeer.sendstates;

import java.io.IOException;
import java.nio.ByteBuffer;
import java.nio.channels.SocketChannel;

import org.bintrotter.apeer.Peer;

public class HandShake implements SendState {

	private Peer 			m_peer;
	private ByteBuffer 		bb;
	private SocketChannel 	sc;
	
	public static final byte[] PID =  new byte[] {'B','i','t','T','o','r','r','e','n','t',' ','p','r','o','t','o','c','o','l'};
	
	public HandShake(Peer peer) {
		
		m_peer = peer;
		bb = null;
		sc = null;
	}
	
	@Override
	public void reset() {
		
		sc = m_peer.channel();
		bb = ByteBuffer.allocate(68);
		bb.rewind();
		bb.put((byte)PID.length);
		bb.put(PID,0,PID.length);
		for(int i=0;i<8;++i)
			bb.put((byte)0);
		
		byte[] infoHash = m_peer.outInfoHash();
		byte[] peerID   = m_peer.outPeerID();
		
		bb.put(infoHash,0,infoHash.length);
		bb.put(peerID,0,peerID.length);
		bb.rewind();
		
		
	}

	@Override
	public States update() {
		
		try {
			
			sc.write(bb);
			
			if(bb.hasRemaining()==false) {
				bb.clear();
				bb = null;
				return States.WAIT_FOR_HANDSHAKE;
			}
			
		} catch (IOException e) {
			
			return States.SHUTDOWN;
		}
		return States.HANDSHAKE;
	}

}
